Biosynthesis of the respiratory formate dehydrogenases from Escherichia coli

TY - JOUR

T1 - Biosynthesis of the respiratory formate dehydrogenases from Escherichia coli

T2 - characterization of the FdhE protein

A1 - Luke,Iris

A1 - Butland,Gareth

A1 - Moore,Kevin

A1 - Buchanan,Grant

A1 - Lyall,Verity

A1 - Fairhurst,Shirley A.

A1 - Greenblatt,Jack F.

A1 - Emili,Andrew

A1 - Palmer,Tracy

A1 - Sargent,Frank

AU - Luke,Iris

AU - Butland,Gareth

AU - Moore,Kevin

AU - Buchanan,Grant

AU - Lyall,Verity

AU - Fairhurst,Shirley A.

AU - Greenblatt,Jack F.

AU - Emili,Andrew

AU - Palmer,Tracy

AU - Sargent,Frank

PY - 2008/12

Y1 - 2008/12

N2 - <p>Escherichia coli can perform two modes of formate metabolism. Under respiratory conditions, two periplasmically-located formate dehydrogenase isoenzymes couple formate oxidation to the generation of a transmembrane electrochemical gradient; and under fermentative conditions a third cytoplasmic isoenzyme is involved in the disproportionation of formate to CO2 and H-2. The respiratory formate dehydrogenases are redox enzymes that comprise three subunits: a molybdenum cofactor- and FeS cluster-containing catalytic subunit; an electron-transferring ferredoxin; and a membrane-integral cytochrome b. The catalytic subunit and its ferredoxin partner are targeted to the periplasm as a complex by the twin-arginine transport (Tat) pathway. Biosynthesis of these enzymes is under control of an accessory protein termed FdhE. In this study, it is shown that E. coli FdhE interacts with the catalytic subunits of the respiratory formate dehydrogenases. Purification of recombinant FdhE demonstrates the protein is an iron-binding rubredoxin that can adopt monomeric and homodimeric forms. Bacterial two-hybrid analysis suggests the homodimer form of FdhE is stabilized by anaerobiosis. Site-directed mutagenesis shows that conserved cysteine motifs are essential for the physiological activity of the FdhE protein and are also involved in iron ligation.</p>

AB - <p>Escherichia coli can perform two modes of formate metabolism. Under respiratory conditions, two periplasmically-located formate dehydrogenase isoenzymes couple formate oxidation to the generation of a transmembrane electrochemical gradient; and under fermentative conditions a third cytoplasmic isoenzyme is involved in the disproportionation of formate to CO2 and H-2. The respiratory formate dehydrogenases are redox enzymes that comprise three subunits: a molybdenum cofactor- and FeS cluster-containing catalytic subunit; an electron-transferring ferredoxin; and a membrane-integral cytochrome b. The catalytic subunit and its ferredoxin partner are targeted to the periplasm as a complex by the twin-arginine transport (Tat) pathway. Biosynthesis of these enzymes is under control of an accessory protein termed FdhE. In this study, it is shown that E. coli FdhE interacts with the catalytic subunits of the respiratory formate dehydrogenases. Purification of recombinant FdhE demonstrates the protein is an iron-binding rubredoxin that can adopt monomeric and homodimeric forms. Bacterial two-hybrid analysis suggests the homodimer form of FdhE is stabilized by anaerobiosis. Site-directed mutagenesis shows that conserved cysteine motifs are essential for the physiological activity of the FdhE protein and are also involved in iron ligation.</p>

KW - Bacterial respiration

KW - Formate dehydrogenase

KW - Enzyme biosynthesis

KW - Molecular chaperone

KW - BACTERIAL 2-HYBRID SYSTEM

KW - CRYSTAL-STRUCTURE

KW - WOLINELLA-SUCCINOGENES

KW - CONTAINING ENZYMES

KW - NITRATE REDUCTASE

KW - TRANSPORT PATHWAY

KW - EXPORT PATHWAY

KW - COMPLEX

KW - IDENTIFICATION

KW - TRANSLOCATION

U2 - 10.1007/s00203-008-0420-4

DO - 10.1007/s00203-008-0420-4

M1 - Article

JO - Archives of Microbiology

JF - Archives of Microbiology

SN - 0302-8933

IS - 6

VL - 190

SP - 685

EP - 696

ER -